Crying during sex

So today I did the worst thing I cryed while making love to my boyfriend he asked why I was crying  but honestly I wasn't sure why and I told him it was because I just missed him I am working and goin to school full time and it hard to get time with him and now he is hanging out more with his guys and that's great because I don't want him to be lonely when I can't  be around but i don't know if I am jealous of his friends I have no idea and it hurts me because I can't explain it to him Any advice I have been with him for seven years and I never knew I could love some one so much I am just not myself